Fume hood

ABSTRACT

A fume hood including a housing having a flow through inlet and a flow through outlet; the flow through outlet being in communication with an opening in a roof and the flow through inlet is concentrically disposed above and spaced from a discharge of a furnace; the hood being provided with a vertically extending baffle skirt completely surrounding the housing, the lower extremity of the vertically extending baffle skirt being in fluid tight communication with the outer periphery of the flow through inlet of the housing and the upper extremity of the vertically extending baffle skirt being in fluid tight communication with the roof.

United States Patent De Weese et al.

FUME HOOD Inventors: Daniel P. De Weese, Prospect, Ky.;

Nicholas J. Brozenick, Clarksville, Ind.

American Air Filter Company, Inc., Louisville, Ky.

Filed: Apr. 23, 1974 Appl. No.: 463,293

Assignee:

References Cited UNITED STATES PATENTS 1/1920 Xardell 55/458 X [4 1 July 29,1975

Sharpe 98/115 K Culhane 55/447 X {57] ABSTRACT A fume hood including a housing having a flow through inlet and a flow through outlet; the flow through outlet being in communication with an opening in a roof and the flow through inlet is concentrically disposed above and spaced from a discharge of a furnace; the hood being provided with a vertically extending baffle skirt completely surrounding the housing, the lower extremity of the vertically extending baffle skirt being in fluid tight communication with the outer periphery of the flow through inlet of the housing and the upper extremity of the vertically extending baffle skirt being in fluid tight communication with the roof.

5 Claims, 1 Drawing Figure 11 1' a ll "ll l 1 7 l J 6 ,v 2 i 1 H I. i I I 10b i M 4 1 3 1 15 I 1 f f ll Mn. it: ibya; 's 4 FUME HOOD BACKGROUND OF THE INVENTION The invention relates to fume hoods and more particularly relates to a fume hood for exhausting gases and fumes escaping from a furnace.

In the normal operation of furnaces, specifically electric arc furnaces, heavy fumes in great volume escape from the furnace during operation and accumulate in the furnace shop as the volume is usually beyond the capacity of the ventilating means. It has been customary to install hoods above these furnaces which have a large opening therein with the hoods being spaced from the top of the furnace where the fumes are emitting therefrom with the discharge extending through the roof of the shop. However, it has been found that in many instances the fumes coming off of the furnace, because of drafts and other conditions within the shop, circulate around the hood and move upwards toward the roof with a large portion of particulate matter being deposited on the fume hood. In order to alleviate this problem of particulate build up on the hoods, it has been common practice to provide outwardly extending flange portions around the inlet of the hood to deflect the fumes away from the ceiling wherein the fumes in many instances do not pass up through the hood, but down into the shop area. However, these deflectors have not been completely successful as it has been found that over a long period of time particulate matter has continued to circulate around and over the outwardly extending flange portion and has caused additional particulate matter build up on the hoods as well as the outwardly extending flange portion.

SUMMARY OF THE INVENTION In the present invention, it is recognized that it is desirable to provide a fume hood which prevents build up of material on the top sides thereof. Furthermore, it is recognized that it is desirable to provide a fume hood which is inexpensive to manufacture but yet sturdy in construction.

The present invention advantageously provides a straightforward arrangement for a fume hood which may be utilized in conventional furnace shops. The present invention further provides a fume hood which prevents particulate matter build up on the surface thereof. The present invention even further provides a fume hood which is inexpensive, sturdy and yet effective during operating conditions.

Various other features of the present invention will become obvious to those skilled in the art upon reading the disclosure set forth hereinafter.

More particularly, the present invention provides a hood for a roof for exhausting gases and fumes escaping from a furnace comprising: a housing having a flow through inlet and a flow through outlet therein; and, a vertically extending baffle skirt surrounding and in fluid tight communication at its lower extremity with the outer periphery of the flow through inlet and in fluid tight communication at its upper extremity with a roof, the roof having an opening therein in fluid communication with the housing outlet whereby particulate matter entrained in circulating fumes which is not exhausted through the fume hood is prevented from circulating over and settling on the outer surfaces of the housing.

It is to be understood that the description of the examples of the present invention given hereinafter are not by way of limitation and various modifications within the scope of the presentinvention will occur to those skilled in the art upon reading the disclosure set forth hereinafter.

Referring to the drawing:

The FIGURE is a perspective view, partially cut away, of a fume hood of the present invention.

The fume hood of the present invention includes a housing 1 of pyramidal configuration with sloping sides identifiable by the numerals 2a, 2b, 2c and 2d. The pyramidal configured housing 1 includes an opening 3 spaced from and in concentric alignment with the top of a furnace 4, the furnace 4 having an opening 15 therein wherein in normal operation fumes emit therefrom. The housing 1 is also provided with an outlet in fluid communication with a rectangular configured discharge duct 6 which extends vertically upward to communicate with duct 7, exemplified as cylindrical in shape, which extends through an opening in the roof 8.

The fume hood is further provided with a rectangularly shaped baffle skirt l0, baffle skirt 10 being composed of four vertically extending sheets of light gauge sheet material, only three being shown; namely, 10a, 10b and 10c. Baffle skirt 10 is disposed to communicate in fluid tight relation at its lower terminal end with the outer periphery of a flange portion 9, flange portion 9 being disposed along the outer periphery of the inlet 3. At its upper terminal end, baffle skirt 10 is in fluid tight communication with the roof 8.

In the operation of the furnace 4, when the fumes containing particulate matter are emitting therefrom, a large volume of the fumes emitted pass up through the fume hood inlet 3 and out through the duct 7. However, some of the fumes containing particulate matter which do not find their way into the housing circulate around the vertically extending baffle skirt 10 but because of the fluid tight seal with the roof 8 and the 1 flange 9 fumes containing the particulate matter are prevented from circulating over and settling on the hood 1. Thus, the light gauge vertically extending baffle skirt enables the installation of a fume hood which does not have to be designed for carrying heavy loads as a result of particulate matter settling on the sloping sides 2 thereof or the top portion of the hood 11.

It is realized that various changes may be made to specific embodiments shown and described without departing from the principles of the present invention.

What is claimed is:

1. In combination with a furnace, a fume hood for exhausting gases and fumes escaping from said furnace comprising: a housing having a flow through inlet and a flow through outlet therein; a vertically extending baffle skirt surrounding and in fluid tight communication at its lower extremity with the outer periphery of said flow through inlet and in fluid tight communication at its upper extremity with a roof, said roof having an opening therein in fluid communication with said housing outlet with a fluid tight seal being disposed between said opening and said outlet whereby particulate matter entrained in circulating fumes which is not exhausted through said fume hood is prevented from circulating over and settling on said housing.

2. The fume hood of claim 1 including a vertically extending exhaust duct communicating with said outlet of wherein said inlet to said housing is of larger cross sectional area than said outlet of said housing.

5. The fume hood of claim 3 wherein said vertically extending baffle skirt is of rectangular configuration wherein each side of the baffle skirt at its lower terminal end is in fluid tight communication with each side of the pyramidal configured housing. 

1. In combination with a furnace, a fume hood for exhausting gases and fumes escaping from said furnace comprising: a housing having a flow through inlet and a flow through outlet therein; a vertically extending baffle skirt surrounding and in fluid tight communication at its lower extremity with the outer periphery of said flow through inlet and in fluid tight communication at its upper extremity with a roof, said roof having an opening therein in fluid communication with said housing outlet with a fluid tight seal being disposed between said opening and said outlet whereby particulate matter entrained in circulating fumes which is not exhausted through said fume hood is prevented from circulating over and settling on said housing.
 2. The fume hood of claim 1 including a vertically extending exhaust duct communicating with said outlet of said housing and extending through said opening in said roof.
 3. The fume hood of claim 1 wherein said inlet includes an outwardlY extending flange portion disposed in fluid tight communication with said vertically extending baffle skirt.
 4. The fume hood of claim 1 wherein said housing is of pyramidal configuration with four sloping sides wherein said inlet to said housing is of larger cross sectional area than said outlet of said housing.
 5. The fume hood of claim 3 wherein said vertically extending baffle skirt is of rectangular configuration wherein each side of the baffle skirt at its lower terminal end is in fluid tight communication with each side of the pyramidal configured housing. 